Studies are continuing on the effect of pollen exposure and immunotherapy on total serum antibodies (including IgE) and IgE antibodies alone (as measured by RAST), release of histamine and SRSA from leukocytes of ragweed sensitive patients following challenge with whole ragweed extract (WRE). We plan to use the various "purified" fractions of ragweed such as AgE, AgK RA-3, RA-5 and Pool C for similar studies this coming year. WE will then be able to compare these fractions biologic activity to the WRE. RAST disc inhibition tests employing WRE coupled discs and a standard of pooled lyopholized sera from 10-15 ragweed sensitive patients. The homologous antigen (WRE) in varying dilutions will be mixed with a constant amount of the standard serum. Radioactive anti-IgE will then be added and the amount of inhibition determined. The same technique will be used with the various purified fractions as inhibitors and compared to WRE. Individual sera from ragweed sensitive patients will also be used for these inhibition tests. Ragweed pollen extracts will be obtained on the open market from different commercial producers and the above parameters compared. The use of the above techniques for a method to standardize allergen extracts is continuing and looks promising. Studies of various prostaglandins from cells of ragweed sensitive patients, before and after specific immunotherapy, or on exposure during the pollen season is being pursued vigorously.